The present invention relates to a pharmaceutical composition in the form of a formulation suitable for sucking, the composition containing a combination of at least one astringent active substance with at least one second mucilaginous drug or an extract thereof, for the treatment of, in particular, irritations and inflammatory diseases of the oropharyngeal cavity, dry mouth and cough.
The oral mucosa serves particularly to protect the underlying tissue and acts as a natural barrier against mechanical injuries (lesions) and against the penetration of microorganisms and toxic substances. It moistens the oral cavity and wets food to enable it to be digested.
The laryngeal/pharyngeal cavity is lined with a mucosa the essential component of which is the epithelium. The epithelium is the interface between the human body and ingested substances and forms a complex physicochemical barrier which, supplemented by the mucociliary apparatus, constitutes the first defence against pathogens. Mucus covers the epithelium and provides an additional protection for the mucosa, in which it forms a semi-permeable barrier that allows the exchange of nutrients, water and gases but keeps out pathogenic germs. Mucus is a viscoelastic gel of complex composition which is continuously secreted by intraepithelial cells and salivary glands. The main components of mucus are mucins, large and strongly charged glycoproteins which form the structural framework of the mucosal barrier by cross-linking.
The important factors for mucociliary clearance are the number of cilia, their structure and activity, as well as their coordinated movement. Optimum function is guaranteed at 37° C. and an absolute humidity of 44 mg/dm3 (corresponding to 100% relative humidity). Cold, dry or overheated room air as well as alcohol or nicotine adversely affect the normal function of the mucosa and may lead to mucosal irritation, hoarseness, sore throat and dry cough. Under these circumstances, bacterial colonisation is promoted and pulmonary infections may result.
Often, inflammatory diseases of the oropharyngeal cavity also occur as secondary symptoms of colds and influenza-type infections. These frequently involve pain symptoms that are unpleasant for the patient and cause difficulty in swallowing. Inflammations of the oral cavity e.g., gingivitis, stomatitis or oral mucosal lesions have symptoms that are unpleasant for the patient affected.
Typically, inflammatory diseases of the oropharyngeal cavity are treated by topical therapy, for example in the form of mouth and throat rinses, sprays or lozenges. In serious cases systemic therapy is additionally given, e.g. by administering antibiotics.
In particular, 1-hexadecylpyridinium chloride (international generic name: cetylpyridinium chloride (CPC)) has proved useful for the topical treatment of inflammatory diseases of the oropharyngeal region. It is a quaternary ammonium compound with a bactericidal and fungicidal activity which is used in lozenges, for example. A disadvantage of this active substance is the fact that at high doses and if consumed to excess it may cause gastrointestinal problems, breathing difficulties and increased methaemoglobin formation, particularly in children.
Additionally, 1,3-bis(2-ethylhexyl)-hexahydro-5-methyl-5-pyridinamine (international generic name: hexetidine) has also proved useful as a topical antiseptic or disinfectant for the oral, laryngeal and pharyngeal mucosa and is administered for example as a spray or in the form of mouthwashes or gargling solutions. When used long-term or in high doses, once again gastrointestinal disorders may result or there may be gustatory irritations.
Other active substances for the topical treatment of inflammatory processes of the oropharyngeal cavity are astringent active substances, particularly potassium aluminium sulphate decahydrate (international generic name: alum). This is a salt that is traditionally used to treat injuries in the mouth, gingivitis or mucosal swellings and bleeding. As a result of its astringent effect it also reduces colonisation by germs and can alleviate pain by its effect of reducing swelling. A disadvantage is the feeling of a dry mouth caused by the astringent effect.
Active substances of natural origin are also used, such as so-called mucilaginous drugs or extracts thereof such as for example Icelandic moss (Lichen Islandicus). These mucilaginous drugs contain a high concentration of polysaccharides which form mucilages when combined with water. Used for inflammatory diseases of the oropharyngeal cavity in the form of e.g. lozenges or sprays, they form a protective layer and moisten the mucosa. This additional layer of mucus protects the sensitive mechanical and chemical receptors in the mucosa from external irritations and thereby reduces irritations such as for example scratchiness, hoarseness and irritable cough. Generally, these active substances are used in the form of monopreparations, but do not always achieve the desired success.
The problem of the present invention is, therefore, to provide a pharmaceutical preparation in the form of a solid formulation for the topical treatment of inflammatory diseases of the oropharyngeal region which should at least substantially prevent or reduce the disadvantages of the prior art described above.
The Applicant has now surprisingly found that the problem mentioned above is solved by formulating a pharmaceutical preparation in the form of a fixed dosage of at least one astringent active substance (e.g. alum) with at least one mucilaginous drug and/or an extract thereof (e.g. Icelandic moss). A composition of this kind is particularly suitable in the form of lozenges, produced by compression of powder mixtures or based on hard caramels which may be used for topical application in cases of painful or inflammatory and painful diseases of the oropharyngeal cavity.